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author | Eric Blake <eblake@redhat.com> | 2016-04-28 15:45:27 -0600 |
---|---|---|
committer | Markus Armbruster <armbru@redhat.com> | 2016-05-12 09:47:55 +0200 |
commit | 15c2f669e3fb2bc97f7b42d1871f595c0ac24af8 (patch) | |
tree | d5baa8f103d90e6d13d51d351b869b6cde427413 /docs/qapi-code-gen.txt | |
parent | 56a6f02b8ce1fe41a2a9077593e46eca7d98267d (diff) | |
download | qemu-15c2f669e3fb2bc97f7b42d1871f595c0ac24af8.zip qemu-15c2f669e3fb2bc97f7b42d1871f595c0ac24af8.tar.gz qemu-15c2f669e3fb2bc97f7b42d1871f595c0ac24af8.tar.bz2 |
qapi: Split visit_end_struct() into pieces
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.
Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error. So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().
Generated code in qapi-visit.c has diffs resembling:
|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
| goto out_obj;
| }
| visit_type_ACPIOSTInfo_members(v, obj, &err);
|- error_propagate(errp, err);
|- err = NULL;
|+ if (err) {
|+ goto out_obj;
|+ }
|+ visit_check_struct(v, &err);
| out_obj:
|- visit_end_struct(v, &err);
|+ visit_end_struct(v);
| out:
and in qapi-event.c:
@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
| goto out;
| }
| visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, ¶m, &err);
|- visit_end_struct(v, err ? NULL : &err);
|+ if (!err) {
|+ visit_check_struct(v, &err);
|+ }
|+ visit_end_struct(v);
| if (err) {
| goto out;
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Diffstat (limited to 'docs/qapi-code-gen.txt')
-rw-r--r-- | docs/qapi-code-gen.txt | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index b4ae1be..d135847 100644 --- a/docs/qapi-code-gen.txt +++ b/docs/qapi-code-gen.txt @@ -899,10 +899,12 @@ Example: goto out_obj; } visit_type_UserDefOne_members(v, *obj, &err); - error_propagate(errp, err); - err = NULL; + if (err) { + goto out_obj; + } + visit_check_struct(v, &err); out_obj: - visit_end_struct(v, &err); + visit_end_struct(v); out: error_propagate(errp, err); } @@ -1007,7 +1009,10 @@ Example: goto out; } visit_type_UserDefOneList(v, "arg1", &arg1, &err); - visit_end_struct(v, err ? NULL : &err); + if (!err) { + visit_check_struct(v, &err); + } + visit_end_struct(v); if (err) { goto out; } @@ -1026,7 +1031,7 @@ Example: v = qapi_dealloc_get_visitor(qdv); visit_start_struct(v, NULL, NULL, 0, NULL); visit_type_UserDefOneList(v, "arg1", &arg1, NULL); - visit_end_struct(v, NULL); + visit_end_struct(v); qapi_dealloc_visitor_cleanup(qdv); } |